How to deal with coking in the pipeline of the atmospheric tower top air cooler in a petrochemical company’s refining unit?
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This is a carbon steel atmospheric tower top air cooler used in the refining unit of a petrochemical company; the medium is oil and gas, with an inlet pressure of 120 and an outlet pressure of 60. The air cooler has been in operation for over a year, and the pipes have developed scale and rust. Only individual units can be shut down for handling. Such systems are mainly subject to electrochemical corrosion of H2S-HCl-H2O. How to deal with corrosion and coking of metals in such usage environments, as well as how to prevent corrosion?
To address the problems of coking and corrosion in the air coolers’ pipes of the atmospheric distillation units in petrochemical companies, the following steps are usually required: 1. **Shutdown cleaning**: Since coking and rust have already formed, it is first necessary to thoroughly clean the pipes while the unit is shut down. Chemical cleaning methods can be used, by adding appropriate chemical cleaners to dissolve coke and rust. 2. **Mechanical cleaning**: After chemical cleaning, high-pressure water jets or mechanical scrubbing can be used to further remove residues from the inner walls of the pipes. 3. **Corrosion protection**: To prevent future corrosion and coking, it is possible to use anti-corrosive coatings to protect the inner walls of the pipes. Select a corrosion-resistant material layer suitable for the H2S-HCl-H2O environment, such as an epoxy resin coating. 4. **Optimize operating parameters**: Adjust parameters such as temperature, pressure, and flow rate to reduce the tendency of corrosion and coking at high temperatures. 5. **Regular Monitoring and Maintenance**: Establish a schedule for regular inspections and maintenance, including the use of online corrosion monitoring techniques, to detect and address corrosion and coking issues promptly. Through these measures, pipeline coking and corrosion can be effectively addressed and prevented, extending the service life of the equipment and ensuring production safety. .